Preserve RPG Maker XP Trigger Semantics During Migration

[AerunDev]

As a RPG Maker XP project creator migrating to Pokémon Studio v3
I want existing page trigger behavior to be preserved
so that my project continues to behave consistently after migration

Acceptance Criteria

• RPG Maker XP pages are converted into Pokémon Studio triggers.
• Existing page priority behavior is preserved.
• Converted priorities are visible to users.
• The last RMXP page becomes the highest-priority trigger after migration if relevent.
• Local Switch behavior remains unchanged.
• Migration results are deterministic and documented.